Psicolinguistica

429

British Journal of Psychology (2004), 95, 429–455 q 2004 The British Psychological Society www.bps.org.uk

Linguistic relativism and colour cognition
Michael Pilling* and Ian R. L. Davies
University of Surrey, UK
Native speakers of two languages (English and Ndonga) were compared on three colour cognition tasks (sorting, triads and visual search) in a test of the linguistic relativityhypothesis (Whorf, 1956). The colour lexicons of these two languages differ because Ndonga has no basic terms for ORANGE , PINK and PURPLE , and stimuli were chosen to exploit this difference. On the sorting task (sorting into similarity-groups) for each language, nominally similar colours were grouped together more often than nominally dissimilar colours. On the triads task (choosing the mostdifferent of three colours), when the most nominally isolated colour differed for the two languagegroups, each group tended to choose their nominal isolate. On the search task (scanning for target colours among distractors), targets were either in a different English category than distractors (cross-category), or some distractors were in the same English category as distractors (within-category).The ‘cost’ in speed of having within-category distractors was much greater for the English than for the Ndonga. Overall, these data suggest that a core universal component is modulated by a small relativist influence. The differences in the visual search task are consistent with language affecting pre-attentive processes (an indirect language effect) as well as exerting on-line influences (a directeffect).

Linguistic colour categories vary across languages (Berlin & Kay, 1969). They vary in their number of ‘basic’ colour categories and in their positions of category boundaries. The perception of colour is also categorical. The colour continuum is perceived as a number of qualitatively discrete categories designated in English by terms such as red, green, yellow and blue (Beare, 1963).Colour perception is also categorical in another sense. The discrimination of colours in different categories is easier (more accurate or faster) than equivalently spaced colours in the same category (e.g. Bornstein & Korda, 1984). Henceforth, this effect will be referred to as categorical perception (CP). The relationship between these two sets of colour categories (linguistic and perceptual) is amatter of debate. For some (Linguistic Relativists) the two systems are isomorphic with language constructing perceptual categories (Whorf, 1956). For others (Universalists), the two systems are less yoked: linguistic categories map onto pre-existing perceptual categories, but not all languages mark all perceptual categories.

* Correspondence should be addressed to Dr Michael Pilling, PsychologyDiscipline, The Open University, Walton Hall, MK7 6AA, UK (e-mail: m.pilling@open.ac.uk).

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Michael Pilling and Ian R. L. Davies

The main concern of this paper is whether, and if so how, linguistic categories affect colour perception.1 If the Universalist position is true, then the distribution of categorical perception across colour space should be universal. On the other hand, if theRelativist position is true, the distribution of categorical perception should co-vary with the distribution of linguistic category boundaries. Here, we report three tests of these opposing positions by comparing speakers of English and Ndonga, languages that differ in the structure of their colour categories, on colour grouping, colour triads and visual search tasks. These tasks were designed tovary in the perceptual –cognitive processes required to perform them. Thus, the profiles across tasks for each language may indicate the mechanisms producing any differences.

Physiology of colour categories
A great deal is known about the physiological basis of colour vision, from genes through the biochemistry of the retinal receptors, to the early stages of neuronal processing (e.g....